The present invention relates generally to fluid treatment systems such as water treatment systems including water softeners, and more particularly to a control valve for a water softening system. It is recognized that many aspects of the present invention can be applied to other types of fluid treatment systems, such as filtering or de-ionizing systems.
Control valve assemblies for fluid treatment systems, such as water softeners, often use pistons equipped with radial ring seals to control the flow of fluids though the control valve assemblies. Such controls are used to periodically seal off certain flow paths and open others, under the control of a timer portion of the control valve. As is known in the art, such water softeners cycle between service, backwash, brine rinse, slow rinse, fast rinse, brine refill, and other operations well known to designers of such equipment. Operation of such valves is described in U.S. Pat. Nos. 8,302,631, 6,644,349, and 6,176,258, all of which are incorporated herein by reference.
There is a continuing need and desire for an improved control valve assembly for a fluid treatment apparatus which is easier to manufacture, assemble, install, and service.